# std::pmr::polymorphic_allocator<T>::allocate_object

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< cpp‎ | memory‎ | polymorphic allocator

template< class U > U* allocate_object( std::size_t n = 1 ); |  | (since C++20)

Allocates storage for n objects of type `U` using the underlying memory resource.

If std::numeric_limits<std::size_t>::max() / sizeof(U) < n, throws std::bad_array_new_length, otherwise equivalent to return static_cast<U*>(allocate_bytes(n * sizeof(U), alignof(U)));.

### Parameters

n | - | the number of objects to allocate storage for

### Return value

A pointer to the allocated storage.

### Notes

This function was introduced for use with the fully-specialized allocator std::pmr::polymorphic_allocator<>, but it may be useful in any specialization as a shortcut to avoid having to rebind from std::pmr::polymorphic_allocator<T> to std::pmr::polymorphic_allocator<U>.

Since `U` is not deduced, it must be provided as a template argument when calling this function.

### Exceptions

Throws std::bad_array_new_length if n > std::numeric_limits<std::size_t>::max() / sizeof(U); may also be any exceptions thrown by the call to resource()->allocate.

### See also

allocate_bytes (C++20) | allocate raw aligned memory from the underlying resource (public member function)
new_object (C++20) | allocates and constructs an object (public member function)
allocate | allocate memory (public member function)
allocate [static] | allocates uninitialized storage using the allocator (public static member function of `std::allocator_traits<Alloc>`)
allocate | allocates memory (public member function of `std::pmr::memory_resource`)

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